<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./lib/vue-2.4.0.js"></script>
</head>
<body>
    <div id="app">
        <input type="text" v-model="n1">

        <select v-model="opt">
            <option value="+">+</option>
            <option value="-">-</option>
            <option value="*">*</option>
            <option value="/">/</option>
        </select>

        <input type="text" v-model="n2">
        <input type="button" value="=" @click="calc">

        <input type="text" v-model="result">

    </div>
</body>
<script>
    var vm = new Vue({
        el:'#app',
        data: {
            n1: 0,
            n2: 0,
            result: 0,
            opt: '+'
        },
        methods:{
            calc(){//计算器算数的方法
                //逻辑:
                // switch(this.opt){
                //     case '+':
                //     this.result = parseInt(this.n1)+parseInt(this.n2)
                //         break;
                //     case '-':
                //     this.result = parseInt(this.n1)-parseInt(this.n2)
                //         break;
                //     case '*':
                //     this.result = parseInt(this.n1)*parseInt(this.n2)
                //         break;
                //     case '/':
                //     this.result = parseInt(this.n1)/parseInt(this.n2)
                //         break;
                // }

                //注意:这是投机取巧的方式，正式开发中尽量少用
                var cideStr = 'parseInt(this.n1)'+this.opt+'parseInt(this.n2)'
                this.result = eval(cideStr)
            }
        }
    })
</script>
</html>